Box spring frame

ABSTRACT

A box spring frame for supporting a mattress used in conjunction with the frame. The box spring frame includes frame means that define an outer perimeter of the box spring frame. The frame means has a plurality of slat members extending therebetween that are each formed to have a top face and a bottom face. A cap member is positioned contiguous to the bottom face of each slat member. The slat members and the cap members are constructed of materials that are lightweight and have strong compression and tensile strengths, respectively. Accordingly, to utilize the strongest characteristics of the slat members and the cap members they are positioned within the frame so that a major portion of the cross-sectional area of each slat member is placed into compression and each cap member is placed in tension when a load is placed on the frame.

O United States Patent 1191 [111 3,717,886 Watts [4 1 Feb. 27, 1973 BOX SPRING FRAME Primary Examiner-Bobby Gay [75] Inventor: Edwin B. Watts, Rosemont, ll]. Assistant ExamineF-Garry Moore Attorney-Hume, Clement, Hume & Lee [73] Assignee: Sealy,Inc., Chicago, Ill.

57 ABSTRACT [22] Filed: Feb. 25, 1971 l 1 1 A box sprmg frame for supportmg a mattress used in PP N05 118,631 conjunction with the frame. The box spring frame includes frame means that define an outer perimeter of 52 u.s. c1 ..s/239 52/730 the Spring frame- The frame means has a plurality [51] Int. (:1 ..A47c 15/30 members extending therehetwee" that are each [58] Field of Search ....5/191, 236, 239, 255; 52/730, h 9 havfia and A CaP 52/732 370 member 18 pos1t1oned contlguous to the bottom face of each slat member. The slat members and the cap members are constructed of materials that are [56] References Cited lightweight and have strong compression and tensile UNITED STATES PATENTS strengths, respectively. Accordingly, to utilize the strongest characteristics of the slat members and the 3,337,882 8/1967 Swatt; ..5/239 cap members they are positioned within the frame so g m? that a major portion of the cross-sectional area of 5/1933 :2 "52/732 each slat member is placed into compression and each 416 907 12/1889 Furn:S :IT52 370 cap member is Placed in tension when a is Placed on the frame.

6 Claims, 4 Drawing Figures BOX SPRING FRAME BACKGROUND OF THE INVENTION This invention relates to improvements in spring units and more particularly to a novel box spring frame construction.

It is common today for bed assemblies to include both a mattress unit and a box spring unit. Box spring units are presently constructed with a frame that comprises slat members supporting a plurality of vertically extending springs. The slat members and the springs provide a firm, yet resilient, vertical support for the mattress. An exemplary box spring frame is described and illustrated in US. Pat. No. 3,337,882.

I-Ieretofore, these box spring frames were formed of either relatively thin, lightweight wood members that did not provide firm, long-lasting support or thicker, heavier wood members resulting in a bulkier box spring unit that was difficult to handle.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a box spring frame which possesses great strength so as to provide firm, long-lasting support for the springs and the associated mattress but which is comparatively lightweight in its overall construction. It is another object to provide a box spring frame which utilizes the strongest strength characteristics of the materials used in construction. It is still a further object to provide a box spring frame which is relatively simple and inexpensive to manufacture.

The foregoing and other objects are realized in accordance with the invention by providing a box spring frame comprising frame means defining an outer perimeter of the box spring frame and having a plurality of slat members extending therebetween. The slat members are each formed so as to have a top face and a bottom face. A cap member is positioned contiguous to the bottom face of each slat member. The slat members and the cap members are constructed of materials that are lightweight and have strong compression and tensile strengths, respectively. Accordingly, to utilize the strongest characteristics of the slat members and the cap members they are positioned within the frame so that a major portion of the cross-sectional area of each slat member is placed into compression and each cap member is placed in tension when a load is placed on the frame.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a box spring frame embodying the features of the present invention;

FIG. 2 is a fragmentary perspective view of the box spring frame illustrated in FIG. 1;

FIG. 3 is a fragmentary perspective view showing a slat member embodying a further modification of the present invention; and

FIG. 4 is a fragmentary perspective view showing a slat member embodying a modification of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT 7 Referring now to the drawings, and more particularly to FIGS. 1 and 2, a box spring frame embodying the preferred features of the present invention is illustrated generally by reference numeral 10. The box spring frame 10 comprises frame means that define an outer perimeter of the frame 10. The frame means includes parallel side rails 12 and parallel end rails 14. A plurality of slat members 16 extend between the side rails 12 so as to be parallel to the end rails 14. The slat members 16 are each formed to have a top face and a bottom face. A center rail 18 extends between the end rails 14 and lies across the 'bottom face of each of the slat members 16 so as to be parallel to the side rails 12. The

' center rail 18 is also formed to have a top face and a bottom face. Cap members 20 are positioned contiguous to the bottom face of each slat member 16 and the center rail 18.

The slat members 16 and the center rail 18 are constructed of materials that are lightweight and have a strong compressive strength. Accordingly, the slat members 16 and the center rail 18 are arranged in the frame 10 so that a major portion of the cross-sectional areas of each of these members are placed into compression as they bend under a load placed on the frame. The cap members 20 are placed into tension as they bend with the slat members 16 andthe center rail 18 under a load placed on the frame.

Thus, the strongest strength characteristics of the slat members 16 and the center rail 18 and the cap members 20 are utilized in the construction of the box spring frame 10.

Considering the box spring frame 10 in more detail, and referring to FIGS. 1 and 2, a generally rectangular support means defining an outer perimeter of the frame 10 includes parallel side rails 12 and parallel end rails 14. The side rails 12 are perpendicular to each of the end rails 14 and are attached thereto by any suitable means. The slat members 16 extend between the side rails 12 so as to lie parallel to the end rails 14.

Each of the slat members 16 are constructed as shown in FIG. 2 so as to have a top face and a bottom face. Construction of the slat members 16 is from any type of the lightweight material that has a strong compression strength, such as wood or plastic. Side fillers 12a are attached to the side rails 12 and facilitate the attachment of the slat members 16 to the side rails 12. The slat members 16 are attached at each end to the side rails 12 and the side fillers 12a by any suitable means.

A center rail 18 is formed as shown in FIG. 2 to have a top face and a bottom face and extend between the end rails 14 so as to lie across the bottom face of the slat members 16 and parallel to the side rails 12. Construction of the center rail 18 is preferably from the same lightweight material used in constructing the slat members 16 so that it possesses a strong compression strength. End fillers 14a are attached to the bottom side of the end rails 14 to facilitate the attachment of the center rail 18 to the end rails 14. The center rail 18 is attached at its ends to the end rails 14 and the end fillers 14a by any suitable means.

The cap members 20 are preferably U-shaped, as seen in FIG. 2, so as to include a face portion 20a and leg portions 20b. Each cap member 20 is formed from any type of lightweight material that has strong tensile strength, such as 22-gauge cold rolled steel. The cap members 20 can be formed directly on the slat members l6 and the center rail 18 or separately therefrom and, once formed, the cap members 20 are united by any suitable means to each of the slat members 16 and the center rail 18. When the cap members 20 are united to the slat members 16 and center rail 18 the face portion 20a is contiguous to the bottom face of each of the slat members 16 and the center rail 18. The leg portions 20b extend along the sides of the slat members l6 and the center rail 18 and provide positioning means for the face portion 200.

When a normal force is directed on the frame 10 the slat members 16 and the center rail 18 bend. In bending, the top cross-sectional half of each slat member 16 and center rail 18 is placed in compression and the bottom cross-sectional half of each slat member 16 and center rail 18 is placed in tension. However, when the cap member 20 is placed on the bottom face of each of the slat members 16 and the center rail 18, a majority of the cross-sectional area of each slat member 16 and center rail 18 is placed in compression. As herein disclosed, the slat members 16 and center rail 18 are constructed of materials possessing a compression strength stronger than the tensile strength. Thus by placing a majority of the cross-sectional area of each slat member 16 in compression and a majority of the crosssectional area of the center rail 18 in compression, the strongest strength characteristic of the slat members 16 and center rail 18 are utilized.

The cap member 20 also bends when a normal force is directed on the frame 10. The face portion 20a is placed in tension which utilizes the strongest strength characteristic for the material used to form the cap member 20. As the leg portions 20b only position the face portion 20a on the bottom faces of each of the slat members 16 and the center rail 18 and are not meant to add strength to these members, their tendency to be placed in compression and to buckle slightly is not a detrimental feature.

In a second embodiment of the invention, illustrated in FIG. 3, a fragmentary portion of the slat member 16 is shown having a cap member 120 positioned thereon. The operation of the cap member 120 is the same as the cap members 20 described in the preferred form of the invention with the exception that the structure is modified by having leg portions l20b formed so as to have rolled edges that grip into the slat member 16 and thus unite the cap member 120 to the slat member 16. The cap member 120 is united in a similar manner to the center rail 18.

In a third embodiment of the invention, illustrated in FIG. 4, a fragmentary portion of the slat member 16 is shown having a cap member 220 positioned on the bottom face thereof. The operation of the cap member 220 is the same as the cap member 20 described in the preferred form of the invention. However, the structure of the cap member 220 is modified by having the cap member 220 comprised of only a face portion 220a. The face portion 220a is united to the bottom face of the slat members 16 by any suitable means, such as nailing or gluing.

While the preferred embodiment of the present invention has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

We claim: l. A box spring frame for supporting a mattress,

comprising:

frame means of generally rectangular configuration comprising a pair of opposed side rails and a pair of opposed end rails;

slat means including a plurality of individual slat members of a length extending between said side rails in spaced parallel relation to one another and said opposed end rails, said slat members each having a top face and a bottom face and being of a predetermined thickness therebetween that is less than the width of said individual slat members;

cap means including a plurality of individual cap members each formed of a sheet metal material of a thickness substantially less than that of said slat members and each having a normally planar portion of a length and width corresponding generally to that of said individual slat members with said planar portions of said cap members being united to the bottom faces of respective ones of said slat members, said slat members and said cap members bending when a normal load is placed on said frame means so that a major portion of the crosssectional area of each of said slat members is placed in compression and a major portion of the cross-sectional area of the planar portions of said cap members are placed in tension.

2. The box spring frame of claim 1 in which said planar portions of said cap means are adhesively bonded to said bottom faces of said slat members.

3. The box spring frame of claim 1 in which said cap members consist of planar sheets.

4. The box spring frame of claim 1 in which said cap members each include opposed edge portions integral with said planar portion such that said cap members are each of a generally U-shaped cross-section with said edge portions of each cap member being contiguous the edges of its associated slat member.

5. The box spring frame of claim 4 in which the terminal parts of the leg portions of each of said cap members are rolled inwardly toward one another and into gripping relation with the edge portions of its associated slat member.

6. The box spring frame of claim 5 and further including a center rail extending between said end rails in parallel relation to said side rails and lying beneath each of said slat members, said center rail being of rectangular cross-section and having a top face contiguous said slat members and a bottom face, and in which said cap means includes a cap member secured to said bottom face of said center rail. 

1. A box spring frame for supporting a mattress, comprising: frame means of generally rectangular configuration comprising a pair of opposed side rails and a pair of opposed end rails; slat means including a plurality of individual slat members of a length extending between said side rails in spaced parallel relation to one another and said opposed end rails, said slat members each having a top face and a bottom face and being of a predetermined thickness therebetween that is less than the width of said individual slat members; cap means including a plurality of individual cap members each formed of a sheet metal material of a thickness substantially less than that of said slat members and each having a normally planar portion of a length and width corresponding generally to that of said individual slat members with said planar portions of said cap members being united to the bottom faces of respective ones of said slat members, said slaT members and said cap members bending when a normal load is placed on said frame means so that a major portion of the cross-sectional area of each of said slat members is placed in compression and a major portion of the cross-sectional area of the planar portions of said cap members are placed in tension.
 2. The box spring frame of claim 1 in which said planar portions of said cap means are adhesively bonded to said bottom faces of said slat members.
 3. The box spring frame of claim 1 in which said cap members consist of planar sheets.
 4. The box spring frame of claim 1 in which said cap members each include opposed edge portions integral with said planar portion such that said cap members are each of a generally U-shaped cross-section with said edge portions of each cap member being contiguous the edges of its associated slat member.
 5. The box spring frame of claim 4 in which the terminal parts of the leg portions of each of said cap members are rolled inwardly toward one another and into gripping relation with the edge portions of its associated slat member.
 6. The box spring frame of claim 5 and further including a center rail extending between said end rails in parallel relation to said side rails and lying beneath each of said slat members, said center rail being of rectangular cross-section and having a top face contiguous said slat members and a bottom face, and in which said cap means includes a cap member secured to said bottom face of said center rail. 